They suggested children - as well as adults playing with the toys - should wear protective eye goggles.

“It is important to note that the risk of having an eye injury with the Nerf darts comes from the fact that a projectile can harm when it travels fast enough,” the authors stated.

Oli Scarff via Getty Images

The report, issued via the Press Association, cited one 32-year-old man who was shot in the eye from eight metres away by a child with a Nerf gun. He suffered blurred vision and a red eye.

A 43-year-old woman was shot in her right eye from one metre away and complained of blurred vision and a sore eye.

And an 11-year-old child suffered a shot in his right eye from a distance of two metres. He developed swelling of the outer and inner layers of the eye from the force and speed of the bullet fired by the gun.

All the patients were examined and given eye drops, the researchers said. After follow ups, the patients sight returned fully.

They also pointed out that examination of non-branded, cheaper bullets that fit Nerf guns are on sale, showed them to be harder than the ones made by Nerf gun manufacturers Hasbro.

“One of the patients in our case series reported that their eye was shot by a Nerf gun bullet that was purchased online,” they said.

“It was apparent on digital examination by the two authors of this case series that there is an obvious difference in the firmness of the Nerf gun bullet head.

“The unlabelled brand by which the patient was injured was more firm.

“There is no evidence that had the patient been shot with the official Nerf gun bullets supplied by the gun supplier that the injury would have been less severe.

“It was not possible for the other two patients to confirm whether or not the eye was shot by a labelled or unlabelled Nerf gun bullet.”

The authors concluded: “This case series emphasises the seriousness of ocular injury from Nerf gun projectiles and calls into consideration the need for protective eyewear with their use.

“It also calls for reconsideration of the safe age limits for Nerf gun use in children.”

Commenting on the findings, Katrina Phillips, CEO, from the Child Accident Prevention Trust (CAPT) told HuffPost UK: “These sorts of guns are growing in popularity and new guns are being released all the time, so it’s helpful for parents to know that doctors are seeing serious accidents with children’s eyes.

“They can warn their children not to fire the guns into anyone’s faces and decide whether to get some eye protection for their child. It would be great to see manufacturers providing eye protection, that’s appealing to children, alongside the guns.”

A spokeswoman for Hasbro told Sky News: “Product safety is of utmost concern at Hasbro. Nerf products are designed based on years of consumer insights and research and undergo rigorous reviews and testing to assure that they are safe and fun to play with and meet or exceed global standards and regulations.

“Nerf foam darts and foam rounds are not hazardous when used properly. Consumers must never aim Nerf blasters at a person’s eyes or face, should only use the foam darts and foam rounds designed for specific Nerf blasters and never modify darts or blasters.”